Our 9 favorite - and least-favorite - Summer Glau roles

Sci-fi goddess Summer Glau is headed for Alphas tonight on Syfy and, of course, she has superpowers, along with an unusual new hairstyle. It looks like Glau racks up another standout sci-fi role as a powerful Alpha named Skylar who can build amazing inventions.

Glau, who's made a habit of playing kick-ass, often unstable sci-fi babes, has put together an impressive body of work so far. So, we decided to rank our nine favorite and least-favorite Summer Glau roles. Where Alphas Skylar will stand once the dust clears, we'll leave that for you to decide.

Here's our list from the best to the not-so-memorable:

1. Firefly and Serenity - River Tam

It was only the second television role of her career, but Glau embraced her inner crazy and made River Tam one of the most interesting and mysterious characters on television. River, along with her brother, Simon, was on the run from the Alliance, who'd spent plenty of time before that messing with her head. Firefly creator Joss Whedon used Glau's natural grace from her years as a ballerina to hang her off ceilings and beautifully kick bad-guy butt. While Firefly only lasted one short, short season, when we finally see River take on the Reavers in Whedon's film, Serenity, and win, it's an awesome moment.

Here are River scenes from Firefly and Serenity:

2. Terminator: The Sarah Connor Chronicles - Cameron Phillips

Glau as a Terminator seems like a natural choice now. After all, no one said that Terminators had to look like Arnold Schwarzenegger. Considering her character could only pretend to have emotions, Glau still managed to infuse Cameron with plenty of heart, often thanks to John Connor's (Thomas Dekker) smoldering glances. And there were plenty of hints that there was more was going on with Cameron beneath the surface. Unfortunately, Sarah Connor Chronicles was canceled after two seasons, with the character's stories unfinished.

Here's a promo for the series with plenty of Cameron:

3. The Big Bang Theory - Summer Glau

When the Big Bang Theory guys take a train, Summer Glau sits in their car and funny ensues. She plays herself, although we can't imagine (any more than the guys) why she'd take a train; we're sure if Glau ever considers buying a train ticket for real, this plot—Summer Glau trapped with four geeks on a moving train—will be enough for her to reconsider.

4. The 4400 - Tess Doerner

Glau played a paranoid schizophrenic with the ability to force people to do what she tells them to do. Tess ends up in a touching relationship with the father of 4400 technology, Kevin Burkhoff (Jeffrey Combs), and they go on the run together until they're pulled back into the action. While Tess didn't battle Terminators or Reavers, the character evolved over three of The 4400's four seasons and gave Glau a chance to play a memorable role filled with depth.

Here's a look at Tess on The 4400:

5. The Cape - Orwell

Easily the best thing about The Cape was Glau's Orwell. Her character is smart and sexy and finds herself battling bad guys often in this short-lived series. While there are hints about who Orwell really is and a bubbling of potential for that character, the series as a whole failed Glau and us.

Here's a promo of The Cape:

6. Dollhouse - Bennett Halverson

It was exciting to see Glau added to the cast of Joss Whedon's Dollhouse. And while there was the possibility here for another great Glau character, somehow Bennett left us a bit flat. It was just one of a string of disappointments when it came to Dollhouse, a show that never, for us, lived up to its potential.

Here's a fan-made video of Bennett Halverson on Dollhouse:

7. Angel - Prima Ballerina

Glau's first TV role gave the young former ballerina a break into acting and introduced her to Joss Whedon, who would eventually cast her in Firefly and Dollhouse. Here's a look:

8.Chuck - Greta

There was so much hype about Glau joining her Firefly castmate Adam Baldwin (who plays Casey on Chuck) that the guest shot actually ended up to be a bit of a disappointment. In fact, the entire thing, with different actors playing the mysterious Greta, never really worked. However, this one scene between Greta and Casey almost made the Greta business worthwhile:

9. Mammoth - Jack Abernathy

A rampaging prehistoric mammoth and Summer Glau playing a girl named Jack. What's not to love? One note: Mammoth did score an Emmy nomination for visual effects. It did not win. Here's a look: